make async_std optional, add fs feature

Author: akhilles

Cargo.toml

@@ -16,17 +16,17 @@ features = ["docs"]
 rustdoc-args = ["--cfg", "feature=\"docs\""]
 
 [features]
-default = ["async_std", "cookie-secure"]
+default = ["fs", "cookie-secure"]
 docs = ["unstable"]
 unstable = []
 hyperium_http = ["http"]
-async_std = [] # "async-std" when it is not default
+async_std = ["fs"]
 cookie-secure = ["cookie/secure"]
+fs = ["async-std"]
 
 [dependencies]
-# Note(yoshuawuyts): used for async_std's `channel` only; use "core" once possible.
 # features: async_std
-async-std = { version = "1.6.0", features = ["unstable"] }
+async-std = { version = "1.6.0", optional = true }
 futures-lite = "1.7.0"
 async-channel = "1.4.2"
 
@@ -46,4 +46,4 @@ serde_qs = "0.7.0"
 
 [dev-dependencies]
 http = "0.2.0"
-async-std = { version = "1.6.0", features = ["unstable", "attributes"] }
+async-std = { version = "1.6.0", features = ["attributes"] }

src/body.rs

@@ -357,7 +357,7 @@ impl Body {
     /// res.set_body(Body::from_file("/path/to/file").await?);
     /// # Ok(()) }) }
     /// ```
-    #[cfg(all(feature = "async_std", not(target_os = "unknown")))]
+    #[cfg(all(feature = "fs", not(target_os = "unknown")))]
     pub async fn from_file<P>(path: P) -> io::Result<Self>
     where
         P: AsRef<std::path::Path>,
@@ -477,7 +477,7 @@ impl AsyncBufRead for Body {
 
 /// Look at first few bytes of a file to determine the mime type.
 /// This is used for various binary formats such as images and videos.
-#[cfg(all(feature = "async_std", not(target_os = "unknown")))]
+#[cfg(all(feature = "fs", not(target_os = "unknown")))]
 async fn peek_mime(file: &mut async_std::fs::File) -> io::Result<Option<Mime>> {
     // We need to read the first 300 bytes to correctly infer formats such as tar.
     let mut buf = [0_u8; 300];
@@ -491,7 +491,7 @@ async fn peek_mime(file: &mut async_std::fs::File) -> io::Result<Option<Mime>> {
 
 /// Look at the extension of a file to determine the mime type.
 /// This is useful for plain-text formats such as HTML and CSS.
-#[cfg(all(feature = "async_std", not(target_os = "unknown")))]
+#[cfg(all(feature = "fs", not(target_os = "unknown")))]
 fn guess_ext(path: &std::path::Path) -> Option<Mime> {
     let ext = path.extension().map(|p| p.to_str()).flatten();
     ext.and_then(Mime::from_extension)